# Copyright 2020 Red Hat, Inc. Jake Hunsaker <jhunsake@redhat.com>

# This file is part of the sos project: https://github.com/sosreport/sos
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions of
# version 2 of the GNU General Public License.
#
# See the LICENSE file in the source distribution for further information.

import re

from threading import Lock


class SoSMap():
    """Standardized way to store items with their obfuscated counterparts.

    Each type of sanitization that SoSCleaner supports should have a
    corresponding SoSMap() object, to allow for easy retrieval of obfuscated
    items.
    """

    ignore_matches = []

    def __init__(self):
        self.dataset = {}
        self.lock = Lock()

    def ignore_item(self, item):
        """Some items need to be completely ignored, for example link-local or
        loopback addresses should not be obfuscated
        """
        for skip in self.ignore_matches:
            if re.match(skip, item):
                return True

    def item_in_dataset_values(self, item):
        return item in self.dataset.values()

    def add(self, item):
        """Add a particular item to the map, generating an obfuscated pair
        for it.

        Positional arguments:

            :param item:        The plaintext object to obfuscate
        """
        with self.lock:
            self.dataset[item] = self.sanitize_item(item)
            return self.dataset[item]

    def sanitize_item(self, item):
        """Perform the obfuscation relevant to the item being added to the map.

        This should be overridden by each type of map that subclasses SoSMap

        Positional arguments:

            :param item:        The plaintext object to obfuscate
        """
        return item

    def get(self, item):
        """Retrieve an item's obfuscated counterpart from the map. If the item
        does not yet exist in the map, add it by generating one on the fly
        """
        if self.ignore_item(item) or self.item_in_dataset_values(item):
            return item
        if item not in self.dataset:
            return self.add(item)
        return self.dataset[item]

    def conf_update(self, map_dict):
        """Update the map using information from a previous run to ensure that
        we have consistent obfuscation between reports

        Positional arguments:

            :param map_dict:    A dict of mappings with the form of
                                {clean_entry: 'obfuscated_entry'}
        """
        self.dataset.update(map_dict)